When drilling wells into the earth, a string of drill pipe is rotated and driven into the earth to form the hole or well through which the fluid will be extracted to the surface. The end of the string of drill pipe includes a cutting head which dislodges the earthen material as the drill pipe string is driven deeper into the earth. Water is typically flowed into the well being drilled, with the water and removed earthen material flowing upwardly around or within the rotating drill pipe and outwardly of the well being drilled.
The drill pipe string is made up of a plurality of pipe segments which are connected end-to-end. The drill string is rotated and advanced into the earth until another segment of drill pipe is needed to extend the assembled length of drill pipe segments further. Then, the rotation of the drill string is stopped and the device imparting the rotary motion to the drill string is moved out of the way to enable another segment of drill pipe to be secured to the drill string. Further at the conclusion of drilling, the process is reversed whereby the drill string must be raised with each segment of drill pipe being sequentially removed as it exits the well.
The mechanism which is used to grasp a segment of drill pipe, whether separate from or attached to the drill string, is commonly known as a drill pipe elevator. Such are typically hinged, clam-shell devices which can be opened to be received about a segment of drill pipe and subsequently closed to be clasped about an upper end of the drill pipe segment. The drill pipe segments typically have projecting flanges at their ends or diametrically enlarged neck portions at an outer end thereof which prevents the drill pipe from sliding through the drill pipe elevator. The drill pipe elevator typically includes diametrically opposed rings which can be grasped by cables, hooks, links, or bails of an elevator mechanism for raising and lowering the drill pipe elevator and correspondingly a drill pipe segment, including an entire drill string, received thereby.